Rotary drum



-' Se t. 20, 1938. w, RENTROCK 2,130,744

ROTARY DRUM Filed March 26, 1937 Patented Sept. 20, 1938 UNITED? STATES? ROTARY DRUM Wilhelm Reintrock, Podsused,. near Zagreb, Yugo-- slavia, assignor. to the firm Fried Krupp Grusonwerk Aktiengesellschaft, Magdeburg-Buckau, Germany Application March 26,1937, Serial No. 133330 In :Germany; February 1051936;

3 Claims. (01. sa s)- Myinvention relates to rotary: drums for grinding and :similar. operations, more particularly. to

such drumslof uniform .circumferential shape provided with longitudinal, partition walls arranged in star fashion whereby thesdrum'is di-,

vided, into i a :number ofx chambers' surrounding the axis otrotation.

The charging of the individual chambers and the discharge, therefrom takes place in such rirumsthroughthe transverse walls of the drum,

of the arrangement is not realized, the power re--.

quiredfor the rotation of;the drum is also in- 0 ;creased; .because the drum isunevenly loaded by the varying charge and in this way a fluctuating drivingaforce is required.

According to myinvention the length of the:

longitudinal partition walls is made smaller than ;ithe distance between the transverse walls xenclosing them, so that they terminate at a distance from xthe said transverse walls at one or both ends. In this way, a free zone is formed in the drum between the end of the longitudinal partitions and the transverse wall. Since the drum is of uniform diameter, there is no step between this free zone and the chambers. Thus, the contents of the individual chambers fall or roll during rotation of the drum partly into this free zone '35 and back into the chambers, whereby a constant compensation automatically progresses between the individual chambers in respect of their filling.

In order to prevent too great a falling or flow of the contents from the chambers, I provide the longitudinal partition walls at their free end with a flange which may extend to the wall of the drum, or I let them abut against a plate which leaves a passage free between the edges of the partition walls and the wall of the drum. The partition walls may also be curved in spiral fashion, preferably near to their free ends, instead of lying parallel to the axis. This curvature may extend. in the direction of rotation of the drum or inversely with respect thereto. It thus conveys the contents of the chambers, in the first case on the charging side and in the second case on the discharging side, more forcefully into the free zone than would a wall of parallel axis, so that the compensation is increased, while in both the other casesithas an impeding action and thusl'brings about. a sifting during falling out.

In order .th-atrmyfinvention may be clearly understood andrreadily carried into effect the same will Enowbe more fully. described with reference to the accompanying drawing illustrating a constructional example of the invention.

Figure 1 represents agrinding drum in longitudinal: 1 section.

Figuresx2-and3 representrcross sections on the lines -II+II and 'III III-rof Figure 1 respectively.

The: improved 'machine is mounted on a suitably-constructed frame :I U; in which is journaled a rotary drum consisting of the peripheral wall ll and the'two end walls 12 and IS the former carrying theitrunnion I4." A, suitable driving device.:|5-is provided forvimparting a rotary motion to, the said ydrum; By the feeding spout I6 thematerial to-behandled is charged to the drum through the :passage of the trunnion I4. At the discharging end of the drum the stationary outlet |'|;.isi,provided'embracing the end wall IS. The interior-space of the drum is divided into zones A and-:B by thetransversewalls |8, l9 and 2D, thesewalls being provided with passages in the form of slots" In the said zones, longitudinal partitions are arranged, the partitions 2| between the transverse walls l8 and I9 terminating at each end at a distance from the latter, so that between them and the transverse walls at each end a free zone B traversing the entire cross section of the drum is formed. The longitudinal partitions 2| are, as is shown in Figure 2, arranged in star fashion to subdivide the inner space into grinding chambers K. At their edges facing towards the transverse wall l8, they are provided with flanges 22 on that side on which the contents of the drum are situated during upward rotation in the direction of the arrow ac in Figure 2, the outer ends 22 of the said flanges extending to the peripheral wall ll of the drum, while their inner ends 22" form a'disc about the axis.

At the other end, that is, on the side facing towards the transverse wall IS, the partition walls 2| terminate in a spirally curved part 2|, which is curved in the direction of rotation of the drum, as is shown in Figure 2.

The material which has passed through the transverse wall l8 is uniformly distributed from the free zone in front of the longitudinal partitions 2| into the individual chambers formed by the said partitions 2|. The flanges 22 prevent material required for the proper filling from returning, but allow any surplus which may have passed into any of the chambers to fall back into the initial free zone.

The spiral formation 2! of the partitions 2| at the outlet end favours the passing out of the ground material.

The longitudinal walls 23, which are arranged in zone B between the transverse partitions l9 and 28, as is shown in Figure 3, are not inserted radially, but each partition forms an angle with the radial direction whereby a solid part 24 about the axis of the drum is formed, which remains unused. As this zone serves for the finer grinding, the longitudinal partitions here lie level and parallel to the axis of the drum. They extend to the closing transverse wall 20, through which the completely ground material passes out.

My invention affords the further advantage that the individual chambers are accessible from the free zone, and may therefore be cleaned, and when necessary charged with new grinding bodies from this zone. It is therefore no longer necessary to provide a man-hole in the jacket of the drum for each individual chamber, whereby the drum is cheapened and strengthened.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:

1. In a device of the kind described, a peripheral Wall forming a drum of uniform cross-section, means supporting said drum for rotation, means for rotating said drum, perforated transversewalls in said drum, and longitudinal partitions between said transverse walls extending from the axial midsection of the drum to the peripheral wall thereof and terminating in a closed central hub to subdivide the inner space of the drum into grinding chambers, the axial length of said partitions being sufficient to cause a repeated tumbling of the material in its travel along them, but less than the distance between the transverse walls enclosing them, so that at leastat one end of said partitions there is a free zone between the ends of the partitions and the adjacent transverse wall which communicates openly with said grinding chambers.

2. In a device of the kind described, a peripheral Wall forming a drum of uniform cross-section, means supporting said drum for rotation, means for rotating said drum, perforated transverse Walls in said drum, and longitudinal partitions between said transverse walls extending from the axial midsection of the drum tothe peripheral wall thereof and terminating in a closed central hub to subdivide the inner space of the drum into grinding chambers, the axial length of said partitions being sufficient to cause a repeated tumbling of the material in its travel along them, but less than the distance between the transverse walls enclosing them, so that' at least at one end of said partitions there is a free zone between the ends of the partitions and the adjacent transverse wall which communicates openly with said grinding chambers, the space between each adjacent pair of partitions being wholly open to said free zone, with the exception of a flange on each partition extending slightly above the side of the partition which faces up- ,wardwhen the partition is moving upward, to

hold the material to be ground to a certain depth on the partition.

3. In a device of the kind described, a peripheral wall forming a drum of uniform cross-section, means supporting said drum for rotation, means for rotating said drum, perforated transverse walls in said drum, and longitudinal partitions between said transverse walls extending from the axial midsection of the drum to the peripheral wall thereof and terminating in a closed central hub to subdivide the inner space of the drum into grinding chambers, the axial length of said partitions being sufiicient to cause a repeated tumbling of the material in its travel along them, but less than the distance between the transverse walls enclosing them, so that at least at one end of said partitions there is a free zone between the ends of the partitions and the adjacent transverse wall which communicates openly with said grinding chambers, said partitions being substantially plane for the most part, but spirally curved at their eflluent ends.

WILHELM REINTROCK. 

